The present invention pertains to a clamp for holding elongated members such as pipes, tubes, or wire harnesses to attached members such as an automobile body panel or the like, and in particular pertains to an anti-vibration clamp which does not transfer vibration from elongated members such as pipes, tubes or wire harnesses to attached members such as body panels or the like, and vice-versa.
A pipe clamp comprises a clamp portion for holding a pipe and a locking portion for affixing to an attached member such as an automobile body panel or the like, whereby the pipe is held by the clamp portion and the locking portion is affixed to the attached member. The clamp portion has an open part at the top for receiving pipes, and is constituted to house a pipe in the U-shaped space formed by a pair of side wall portions and the bottom portion; the housed pipe is held so that it cannot pull out of the clamp portion. There are also instances where the top of the clamp portion is covered by a cover. The locking portion has an affixing means for attaching to an attached member such as a body panel, and is affixed to the attached member such an automobile body panel.
In some cases, vibration can occur in pipes due to the pulsation of fluids passing through the pipe, etc. Transfer of this type of vibration through the pipe clamp to the vehicle side should be avoided. It is also necessary that vehicle-side vibration not be transferred through the pipe clamp to the pipe.
For this reason, there are pipe clamps with enhanced vibration-proof characteristics achieved by forming the clamp body of hard resin and forming rubber members of rubber or soft resin to hold pipes. In such pipe clamps, the pipe does not directly contact the clamp body made of hard resin, so such clamps are highly vibration-proof.
However, in such pipe clamps, if the pipe is wide, or if pipe pitches differ, separate rubber members and separate clamp bodies must be used. This required fabrication of different rubber members and clamp bodies for each design.
Also, to avoid incorrectly assembling a specified rubber member to an incorrect other rubber member, and to avoid assembly in the wrong direction of attachment, a mis-assembly prevention mating portion, or a mis-assembly prevention stop, was required. This resulted in more complicated metal molds for clamp bodies and rubber members.
FIGS. 1A-3B illustrate an example of a conventional vibration-proof clamp. FIG. 1A is a front elevation of a conventional vibration-proof clamp; FIG. 1B is a cross-section thereof. FIG. 2A is a perspective view of a vibration-proof clamp rubber member; FIG. 2B is a cross-section thereof.
This vibration-proof clamp includes a clamp body 5 made of hard resin for attaching to a stud, a cover 3 for covering the top side of clamp body 5, one rubber member 4 attached to clamp body 5, and a separate rubber member 4 attached to cover 3. Rubber member 4 attached to clamp body 5 and rubber member 4 attached to cover 3 are the same shape and size. A single rubber member 4 has two pipe holding portions, semicircular in cross section. Two pipes of differing diameters can be held by two sets of rubber members 4 above and below.
Clamp body 5 has a rubber bottom holding portion for holding rubber member 4, and a locking portion 2 for affixing to studs installed on a body panel or the like. A locking claw 2a for locking to a stud or the like is provided on locking portion 2.
As shown in FIGS. 1A and 1B, rubber bottom holding portions 5b, 5c, semicircular in front elevation, are formed on the ends of the rubber bottom holding portion in the width direction. Rubber affixing portion 5a is provided on clamp body 5 for affixing rubber member 4.
Rubber top holding portions 3b, 3c, semicircular in front elevation, are formed in the width direction on the end portions of cover 3.
A rubber affixing portion 3a is provided on cover 3 for affixing rubber member 4.
A main unit locking foot 3d and locking claw 3e are provided as connecting means for joining with clamp body 5. A locking projection 5d is provided on clamp body 5 as a connecting means for joining main unit locking foot 3d and locking claw 3e. When cover 3 and clamp body 5 are joined by a connecting means, a pipe holding space is formed between the two rubber members 4.
As shown in FIGS. 2A and 2B, rubber member 4 has semicircular holding end portions 4b, 4c at the ends in the width direction. Holding end portions 4b, 4c are shaped to conform to rubber bottom holding portions 5b, 5c of clamp body 5. Also, holding end portions 4b, 4c are shaped to conform to rubber top holding portions 3b, 3c on cover 3.
As shown in FIGS. 1B and 2A, rubber member 4 is provided with a rubber affixing portion 5a on clamp body 5, and a rubber projecting portion 4a to which the rubber affixing portion 3a on the cover locks. Rubber member 4 has a pipe holding portion for holding a pipe; ribs 4d, 4e are formed on the pipe holding portion, such that the pipe is supported by ribs 4d, 4e. 
Referring now to FIG. 1, the radius of the clamp body rubber bottom holding portion 5b for holding thin pipe P1 of radius d in FIG. 1A is g; the radius of the clamp body rubber bottom holding portion 5c for holding wide pipe P2 of radius e is f. The center-to-center distance between these two pipes P1 and P2 is a.
A mis-assembly prevention mating portion 8 is provided to separate cover 3, clamp body 5, and rubber member 4 from other covers, clamp bodies and rubber members.
FIG. 3A is a front elevation of a different vibration-proof clamp for holding two pipes; FIG. 3B is a cross section thereof. The FIG. 3A clamp holds the same two pipes P1, P2 as the vibration-proof clamp in FIG. 1A. The center-to-center distance between narrow pipe P1 of radius d and wide pipe P2 of radius e is b.
Since the pipe-to-pipe distance, or pitch, between the two pipes is different from that of the vibration-proof clamp shown in FIG. 1A, the vibration-proof clamp shown in FIGS. 3A and 3B must use a rubber member 4′ different from the rubber member 4 shown in FIG. 1A. A clamp body 5′ and cover 3′ different from the clamp body 5 and cover 3 shown in FIG. 1A must also be used. A “prime” symbol is appended to the reference numerals for the respective members and parts of the vibration-proof clamp in FIGS. 3A, 3B.
Also, in order to distinguish in practice rubber member 4′ used in the FIG. 3A vibration-proof clamp from the rubber member 4 used in the FIG. 1A vibration-proof clamp, a mis-assembly prevention mating portion 8′ and mis-assembly prevention shape 9′ are required.
In cases where, unlike the illustrated example, the FIG. 1A vibration-proof clamp and pipe diameter differ while pipe pitch is the same, a rubber member different from rubber member 4 must be used. A clamp body and cover different from clamp body 5 and cover 3 must also be used.
Thus, when the sizes of the pipes being held are different but the pitches are the same, or when the pitches of the pipes being held are different but the pipe sizes are the same, the rubber members, clamp bodies, and covers used must all be different.
A pipe clamp has therefore been sought with which, to the extent possible, the same clamp bodies and covers and the same rubber members can be used, even when pipe sizes and pitches differ. A pipe clamp with which a specified rubber member can be easily distinguished is also sought.
Patent Citation 1 discloses a pipe clamp comprising a clamp body for holding a pipe or the like, a cover, and a vibration dampening member between the cover and the clamp body, whereby vibration is prevented from being transferred to the pipe by the vibration dampening member.
Multiple ribs project from pipe-facing surface of the vibration dampening member toward the pipe, extending circumferentially from the outside surface of the pipe, separated by intervals in the axial direction of the pipe, and the tip surfaces of the ribs form the pipe holding surface.
In the vibration-proof clamp of Patent Citation 1, each pipe is held by multiple spaced ribs, so the side surface of the pipe is held partially; hence, there is no loss in the vibration dampening effect, even if the strength of the vibration dampening member is raised to increase holding strength.
The vibration-proof clamp of Patent Citation 1 is arranged so that the two vibration dampening members which are mounted between the clamp body and the cover hold multiple pipes from above and below. Therefore, in this clamp, when pipe sizes and pitches differ, separate vibration dampening members are required. Also, a mis-assembly prevention mating portion or mis-assembly prevention shape is required to differentiate vibration dampening members. Finally, separate clamp bodies and covers must be prepared.
Patent Citation 2 discloses a clamp fitted with a substantially U-shaped elastic member between one clamp portion and another clamp portion rotatably linked by a hinge portion. Patent Citation 2 comprises a lock mechanism resistant to removal when one clamp portion is rotated toward the other clamp portion so that the locking surface is engaged.
The clamp of Patent Citation 2 holds a single pipe with two elastic members above and below. If pipe sizes differ, separate vibration dampening members and separate clamp bodies and covers are required.
Patent Citation 3 discloses a clasp and a piping affixing member furnished with a rubber elastic body held by the clasp, for elastically supporting the piping. By providing insertion holes in the clasp and insertion projections in the rubber elastic body, the rubber elastic body can be assembled to the clasp by pressure insertion of the insertion projections into the insertion holes.
The piping affixing member in Patent Citation 3 holds multiple pipes with two rubber elastic bodies above and below. Therefore, when pipe sizes and pitches differ, separate rubber elastic bodies and separate clamp bodies and covers are required.
Therefore, a vibration-proof pipe clamp has been sought with which, to the extent possible, the same rubber members and the same clamp bodies and covers can be used, even when pipe sizes and pitches differ.
A vibration-proof clamp capable of easily distinguishing specified rubber members has also been sought.
Patent Citation 1: Japan Published Unexamined Patent Application 2006-336732=JP4550668.
Patent Citation 2: Japan Published Unexamined Patent Application 2000-205211=JP4036557.
Patent Citation 3: Japan Published Unexamined Patent Application 2005-9613=JP4359080.